Collet chuck



March 29, 1949.

M. L. BENJAMIN ET AL COLLET CHUCK Filed Jan. 25. 1946 INVENTORS MILTONL.BENJAMIN and Y STANLEY S. BENJAMIN M KWM ATTORNEIS UNITED STATESPATENT OFFICE OOLLET CHUCK mitonLBenjmmOieveiondnndBcniamimUnivereityllelrhte, ohiolssids icyS.BenjnminI-Illmrtosoldliiltonl- Application Jlnulry 25, 1.946, serlltlno. 648.884

1 Claims. (Cl. 279-56) 2 The present improvements relate as indicated onwhich the latter figure is taken beinginditochuckeoithetypeinwhiohoteporliketool. catedhythe-line i-l:

or work-pieee.ia ripped by a oontractible and Fig. 3 is a transversesection oi a. detail, the

expansible collet. plane of the section being indicated by the lines Inchucks of this time he coiletis received 5 H on Fire. 1 and 2,respectively:

in a shank formed with an outwardly tapered Fla. 4 is a broken sectionon the same plane as bore and the collet is termed with on external thatoi Fig. 1 but showin: a. modification in consnri ace or correspondinztoner. so that when etruction:

iorced longitudinally inwardly oi the shank it Fit. 5 is a broken endview showing still an- 'wiil be contracted onto the tool or work-piece.other modification:

Where the chuck is employed in heavy duty work Fin. 6 is a sectionalview of the latter taken it is desirable that the angle of the taper inoneson the plane indicated by line 6-6, Fig. 5; and

tion be as little as possible, e. g. 10' or less, in 1'18. 7 is a.broken section of the collet by itself order to increase the wedgeaction between the likewise on the some plans as Fig. 1.

collet and supporting shank so as to provide cor- The main elements ofthe chuck as illustrated respondingly increased gripping action.However. in Figs. 1 and 2 of the drawing are those familln'iiess theangle be considerably meter than lust ierly found in chucks oi the truein question and indicated. e. g. exceeds or the collet is are subject tothe modifications usual in such .not self-releasing, 1. e. will remainwedded in the chucks. Thus the outer element a supporting member eventhou h endwile m 20 hollow cylindrical member i ordinarily referred surethereon be removed. to as the shank. said member being provided at oneprincipal object or the present invention its rear end with internalthreads I whereby it accordingly is to provide means whereby in s may bemounted on a correspondingly externally chuck oi the type in question,where the coasting threaded spindl Howevllr. it will be understood facesare thus oi small angularity. the collet may to that such end 01 themember may equally well be positively and easily torced out or thebore-e: consist oi ashank suitable for connection to a. the shank inorder to release the tool or workrocketed driving member. piece heldwithin the collet. A further object is he fo po t on 3 or e te r a l orto provide such means which may be readily inbore 01' member 1 M 5 otwardly. 6. toward corporated in the chuck structure. without unso t fwa d d of the member. the onri which only encumberlng the same. Stillanother obanoh surface makes to the exis oi the member .iect is toprovide means tor the purpose in cuesbeins p eferably 0' or less hecollet 4. which tion which will not. interfere in my way with is mountedwithin the portion 01 member i just the assembly and disassembly oi thechuck. ndescribed, is formed exterior-1y with a. complengny t presentImprovements 1 g m y; m memory conical surieoe 5 which is designed toimprovement in the construct! 1 t n u coact with such surface I or themember. In involving a m hardening treatment addition. the collet at itsforward end is prohm vided with a conical lace 6 which inclines at an gfa i f Z gzag? that: angle opposite to that oi face 5 and is ofconsiderobly ill-ester unzulmlty. Said face 8 at its To theaccomplishment oi the remains and inner edge is furthermore of greaterdiameter related ends M mmflm' m m than the body of the collet so as toform a. rearmtws hereinafter M11 dumbed wardiy directed shoulder 1thereon which serves l v po d t In e claimsa. purpose presently to hedeccribed.

The annexed drawing andthe following dea The t, as h. is longitudinallyint scription set forth in detail certain mechanism seated b 1 d; 3 n 9which extend alternately embodying the invention. such discloeedmeansfrom opposite ends thereof almost to the other constituting, however.but one of various meend. so that when the collet is forced inwardlyehanical forms in which the principle of the init will be contracted andthus caused to grip the ventionmaybeused.stemorshankoiatoolinsertedwithintheseme In said annexed drawing:

or similarly to grip a work-piece, ii desired. It

Fig. l is a central longitudinal section oi. a will be understood thatthe collet will be made chuck embodying our present improvements; oftempered steel or equivalent metal, so that Fig. 2 is a. treat endelevation thereoi as viewed upon contracting pressure being released itwill from the rizht in Fig. 1, the plane oi the section or expand andresume its normal shape or diameter.

be forcefully withdrawn from within the support-- ing member I. Saidnosepiece, as usual. .is threaded upon the forward portion of the memherI within which the ooliettiswreceived being formed with a polygonalsectionl l: (sesame-:31

to permit engagement of a-wrench or similar tool therewith for thepurpose oi rotating the same. At its outer end said nosepiece islormedwith; inwardly directed flange I: which is adapted}? engage withthe outer inclined bevelled surface I or the collet through the mediumof an interposed -onp0sitely bevelled, ring: 18. Accordingly. when thenose-piece is rotated scratto be moved inwerdiy-.-.onthesunportinsmember I the effect will beito force the-collet-inwardlyand threatentraot the sameidue tozthe engagement of .thecolactinssurfaces :8 andfiisuppiemented'hy thesetion of the ring. it whichassists in contracting the outer bevelled end of the collet.

:Mmlmwnin Fla. 1. such iorwardbevellediece B 01' the coilet and thus therearwardlydnected ,ahoulder Lwhich bounds the-inner edge cf-Lsuch dues;are so loeated relatively to the'oppositely inclined face 6- ot theoolletthet-when the latter is thus rorcedinwardlyflan speeewill bebetween; such shoulder and thenuter undo! :the supporting member I..Mounted in the nose-piece at points-spaced. equal :distaucescircumferentislly :thereebout .are' radially :inwardlyqdirectcd pins orpioneers l. mierab lr :three; in number as. shown. Then this arepreferably reoiprocably' held in corresponding redial-hares: ithrizhe-nosa-piece the outer portionsioi which are enlarged to receiresprings il-heidpin place therein'byia out it. are provided with stems-i8which extendthrough such nuts-end are-rittedat their-outerlende withknurled heads 20. At one-point in the dreami'erence of each nut Jlthcreis-cutaradial slot :or match 2i iadapted to receive a correspondingradial protection on the atem'll'ot-the pin or 91011891 ii.

:As'a'result ot-the construction lust described,

when the projections 21 thus carried bythe-reepective plimzers areseated in the slotell o! the corresponding nuts it, said pins orplunger: under the action of the-corresponding springs will-be caused toprolectradially within the nosepiece into position where they ereadaptedto engage with the rearwardly-directed shoulder 1 -0nthe colletwhen the nose-piece is rotated eo wardly by means of the headsI'lithereon and thereuponsuch heads rotated so as to cause-projections12 on; theplunger stems-to rest oh top of-"the corresponding-nuts it.lfn this position, asshown indottedoutline in' lfl. l, the inner ends ofthe plungers will clear theshoulder'l on the collet.

resiliency erupting In the modified form of construction illustratedinFig. 4 instead oi forming the collet simply with a rearwardly directedshoulder l the letter is formed with an ench'cling groove 25. the onewall It or which will cooperate with the plungers it in the same manneras before.

The fmther-modiflcatlon illustrated in Flat.

oandereiatee-tothe'foimotthersdiellyinwardiy projecting element on thenose-piece which engages the outer end of the collet in the manner andfor the purpose hereinbeiore set forth. Under certain circumstances. andparticularly in slew of the collet where considerable pressure remainsto be exerted in order to force -thc-collet-outwardly in order todisengage the same. thepine or phmgers it, because of the d, area oftheir contact with shoulder I.

may h subject to undue wear and at the same iIIuetratewniy one suchpinthus fitted smith its-erouateehoer it being understood that minrtheMSB-OLPlDBalI-flll'flBJ-Wfll desirably he .emnlosedlequslly sp ced aboutthe circumferen esofHthe-ncse-piece. It will also beunderthllifhiliih-Shfldlfltor such thickness or depth in ets-edictdirection that when the plung- :ers .are moved .tostheir outer positionsthe shoes wiil-cicer-zthevshoulder-l in the some manner as :thelinnenends'or -pinaili clear such shoulder.

In ulating acellet-ni' the-type employed in our presentimpmved chuck itis essential. as indicated. that tempered steel or equivalent metalhemnplondsotnetitwflt possess the necessary to function in the mannerrequired. However. hitemperlng'theccllet uniformlysasrhas heretoiorebeen the practice-the result-hes been-to; harden equally the inner andouter faces. whereas such hardening is objectionable inthe .ceseof suchinner. tool gripping race. r-ln other .words. the slimline action oi thebemore elective-ii the smieee be lelt imits'initial relatively soft"state. we have found-that by properi p s on of earburizing materials andapplication oi heat to the collet, in-theeourseoi its manufacture, thebody thereot mass-he hardeneder tempered as shown bytheedouble-rhatchinezin-Fie. to a substantial depth. inwardly, whilestill leaving the inner porand throughout its entire circumferentialextent. in substantially unhardened'condition. Accordin ly. when thecolletis comm-owed, thetool engaged thereby is ehsag edby suehvsofterinterior face. while the outer face which meet: with the tapered boreortho supportine member is hard enough not only'tc be wear. resistantbut also to impart the desired degree of resiliency to the collet.

-0ther modes'oi' the principle of our invention may'be employed insteadof the one explained. change being made as regards the mechanism hereindisclosed moulded the means stated by any of the following claims or theequivalent or such stated means be employed.

' wethereiore-particulsrly point out and distinctly claim as ourinvention:

-1..In a chuck, the. combination ot a hollow cylindrical supportingmember, a contractible collet reclprocably mounted therein. said memberand collet being formed with co-acting faces whereby the latter iscontracted upon movement inwardly of the former. a nose-piecesurrounding said member and reciprocable longitudinally thereof, aninwardly directed flange on said nosepiece engaging the outer endof saidcollet, whereby the latter may be forced into said member, a rearwardlyfacing shoulder on said collet, and a spring-actuated, radially inwardlyprojecting, Plunger on said nose-piece adapted normally to engage saidshoulder, and means adapted to retain said plunger out of such engagingposition when not desired.

2. In a chuck, the combination of a hollow cylindrical supportingmember, a contractible collet reciprocably mounted therein, said memberand collet being formed with co-acting faces whereby the latter iscontracted upon movement inwardly of the former, a nose-piece threadedupon said member so as to be reciprocable longitudinally thereof uponrelative rotation of said nose-piece and member, an inwardly directedflange on said nose-piece engaging the outer end of said collet, wherebythe latter may be forced into said member upon rotation of saidnose-piece in one direction. a rearwardly facing shoulder on saidcollet, and a plurality of circumferentially spaced, sprmg-actuated,radially inwardly projecting plungers on said nose-piece adapted toengage said shoulder, whereby said collet may be withdrawn from saidmember upon rotation of said nose-piece in the opposite direction.

3. In a chuck, the combination of a hollow cylindrical supportingmember, a contractible collet reciprocably mounted therein, said memberand collet being formed with co-acting faces whereby the latter iscontracted upon movement inwardly oi the former, a nose-piece threadedupon said member so as to b reclprocable longitudinally thereof uponrelative rotation of said nose-piece and member, an inwardly directedflange on said nose-piece engaging the outer end of said collet, wherebythe latter may be forced into said member upon rotation of saidnoseplece in one direction, a rearwardly facing shoulder on said collet,a plurality of circumferentlally spaced, spring-actuated, radiallyinwardly projecting plungers on said nose-piece adapted to engage saidshoulder, whereby said collet may be withdrawn from said member uponrotation of said nose-piece in the opposite direc- 6 tlon, and meansadapted to retain said plungers out of such engaging position whendesired.

4. In a chuck, the combination of a supporting member and a colletlongitudinally reciprocable relative to one another and formed withco-acting faces so arranged that opposite relative movements thereofcauses radial expansion and contraction of said collet, a nose-piecereclprocably connected to said supporting member and engageable with anend of said collet to effect relative movement of said supporting memberand collet in one direction, a shoulder on said collet facing in a.direction opposite to the end thereof engaged by said nose-piece, and aradially inwardly projecting element on and movable longitudinally withsaid nose-piece engageahle with said shoulder to eflect relativemovement of said supporting member and collet in an opposite dlrelation,

5. In a chuck, the combination of a hollow supporting member, acontractible collet reclprocably mounted therein. said member and colletbeing formed with co-acting faces whereby the latter is contracted uponmovement inwardly of the former, a nose-piece reclprocably connected tosaid member, an inwardly directed flange on said nose-piece engaging theouter end of said collet whereby the latter may be forced into saidmember, a rearwardly facing shoulder on said collet, and a. radiallyinwardly projecting element on and reclprocable with said nose-pieceadapted to engage said shoulder for positively moving said colletoutwardly of said supporting member when said nose-piece is movedoutwardly of said member.

MILTON L. BENJAMIN. STANLEY S. BENJAMIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS FOREIGN PATENTS Country Number Number Date 34,404Switzerland June 30, 1905 Norway Mar. 18, 1929

